Squaric acid methine dyes are known compounds. U.S. Pat. No. 3,824,099 describes squarylium dye molecules as photogenerating species in a xerographic photoconductor's charge generation layer. Copending and commonly assigned U.S. patent application Ser. No. 391,746, filed June 24, 1982, now abandoned, discloses purification techniques necessary to make a superior OHSQ generating molecule in this generic family of dyes, having Ames negative properties.